The present invention relates to an opening and closing apparatus of an opening and closing lid of an accommodation box for an object to be processed and a processing system using such an opening and closing apparatus and, more particularly, to an opening and closing apparatus of an opening and closing lid of an accommodation box for accommodating an object to be processed such as a semiconductor wafer in a sealed state and a processing system using such an opening and closing apparatus.
Generally, in order to fabricate a semiconductor integrated circuit such as an IC or an LSI, a film deposition process, an oxidation and diffusion process, an etching process, etc., are repeatedly performed with respect to a semiconductor wafer. Since these processes are preformed by separate processing apparatuses, the semiconductor wafer must be transported between the processing apparatuses. When transporting a semiconductor wafer, adhesion of foreign materials onto the surface of the semiconductor wafer and formation of a natural oxidation film must be prevented so to maintain the yield. Accordingly, the semiconductor wafer is transported while being accommodated in an accommodation box of an object to be processed.
As shown in FIG. 1 and FIG. 2, the accommodation box 2 of an object to be processed has a box container 6, which has an opening part 4 formed on one side thereof and has a semicircular shape on the other side. A plurality of support protrusions 8 are provided on an inner wall surface of the box container 6 so as to support the fringe of semiconductor wafers W. The semiconductor wafers W are accommodated in a multistep state at equal intervals in the vertical direction in a state in which the semiconductor wafers W are supported by the support protrusions 8.
Normally, twenty-five or thirteen wafers W can be accommodated in a single box 2. An opening and closing lid 10 formed of a hollow square plate is attached to the opening part 4 of the box container 6. The opening and closing lid 10 can maintain the box container 6 in a sealed state in a state in which the opening and closing lid 10 is attached to the opening part 4 of the box container, thereby preventing the accommodated wafers W from contacting an atmosphere.
The opening and closing lid 10 is provided with two locking mechanism 12 so that the opening and closing lid 10 can be fixed to the box container 6. Additionally, by releasing the locking mechanism 12, the opening and closing lid 10 can be removed from the opening part 4. Specifically, the locking mechanism 12 has a lock plate 16 rotatably mounted to the opening and closing lid 10 at a substantially middle position in the direction of height via a bearing 14, as also shown in FIG. 3A to FIG. 5. A key groove 18 having an elongated concave shape, which fits to a key member described later, is formed on the lock plate 16. The front of lock plate 16 is covered by a lock plate covering member 22 that has a key insertion hole 20 at a position corresponding to a position of the key groove 18 when it is locked.
The lock plate 16 is engaged with an arm 23, as also shown in FIGS. 3A and 3B and FIG. 4, so as to form a crank mechanism, which converts a circular arc motion into a liner motion. The arm 23 extends in a vertical direction, and a pin 24 is connected to each end of the arm 23. That is, each pin 24 is moved in the vertical direction by rotating the lock plate 16 by 90 degrees in the normal or reverse direction.
An end of each pin 24 is inserted into a pin hole 28 of the upper edge and the lower edge defining the opening part 4 as shown in FIG. 2 (only the upper edge is shown in FIG. 2) so that the opening and closing lid 10 does not separate from the opening part 4 when it is locked. It should be noted that each pin 24 is provided so as to extend vertically through the interior of the hollow opening and closing lid 10. Accordingly, as shown in FIG. 4 or FIG. 5, an unlocked state can be achieved by fitting the key member 26 in the key groove 18 and turning the key member 26 by 90 degrees from the locked state as shown in FIG. 3A so as to move the pin 24 backward to remove the pin 24 from the pin hole 28 (refer to FIG. 2).
Generally, the accommodation box 2 is automatically transported in a processing system provided with an automatic transporting mechanism of the accommodation box and a stock area temporarily storing the accommodation box. Additionally, the key member 26 is operated by an automatic device having the key member 26 so that the opening and closing lid 10 is automatically detached from and attached to the accommodation box 2 according the above-mentioned procedures. However, since the key member 26 is loosely fit in the key groove 18, there is a play between the key member 28 and the key groove 18. Accordingly, when the opening and closing lid 10 is unlocked so as to remove the opening and closing lid 10 from the opening part 4 and support the opening and closing lid 10 by the key member 26, the opening and closing lid 10 may be displaced by being inclined with respect to the key member 26. Accordingly, there is a problem in that the opening and closing lid 10 cannot be completely attached to the opening part 4 due to its disposition when closing the accommodation box 2 by attaching the opening and closing lid 10 to the opening part 4 after the process of the wafer is completed.
In order to solve such a problem, positioning holes 30 are provided to the opening and closing lid 10 so that positioning pins (not shown in the figure), which moves forward and backward together with the key member 26, can be inserted into the positioning holes 30 so as to support the opening and closing lid 10 by sharing the load of the opening and closing lid 10 with the positioning pins. However, since the positioning pins are designed so as to be loosely fitted in the positioning holes 30, the displacement of the opening and closing lid 10 cannot be completely eliminated. Thus, in order to prevent the opening and closing lid 10 from being displaced when the opening and closing lid 10 is removed, a vacuum pad that moves forward and backward together with the key member 26 is provided so as to hold the opening and closing lid 10 in a state in which the front surface of the opening and closing lid 10 is attracted by vacuum. However, in this case, there is a problem in that the opening and closing mechanism of the opening and closing lid 10 becomes complex due to the addition of the vacuum pad mechanism.
It is an object of the present invention to provide an improved and useful opening and closing apparatus of an opening and closing lid of an accommodation box of an object to be processed and a processing system in which the above-mentioned problems are eliminated.
More specific object of the present invention is to provide an opening and closing apparatus of an opening and closing lid of an accommodation box of an object to be processed and a processing system, which can prevent a displacement of the opening and closing lid when the opening and closing lid is removed.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention an opening and closing apparatus for opening and closing an opening and closing lid which closes an opening part of an accommodating box for accommodating an object to be processed and is locked by a locking mechanism,
characterized in that the opening and closing apparatus comprises:
a base table;
a key member mounted to the base table via a bearing mechanism in a state in which the key member is rotatable with respect to the base table and movable in a vertical direction with respect to a front surface of the base table;
a key member turning mechanism which turns the key member in either a normal or reverse directions;
key member turning mechanism moving means for moving the key member turning mechanism in the vertical direction with respect to the base table;
horizontal moving means for moving the base table in a horizontal direction with respect to the accommodation box; and
vertical moving means for moving the base table in a vertical direction with respect to the accommodation box.
According to the above-mentioned invention, the locking mechanism is unlocked by driving the vertical moving means and the horizontal moving means so as to insert the locking member into the key groove of the locking member of the opening and closing lid and turning the key member by the key member turning mechanism. Thereafter, a part of the opening and closing lid is sandwiched and held between the front surface of the base table and the key member by moving the key member turning mechanism moving means. Then, in this state, the opening and closing lid is removed by moving the base table backward by driving the horizontal driving means. Since the opening and closing lid is sandwiched and held by the key member and the base table, the opening and closing lid is prevented from being displaced with respect to the based table.
In the above-mentioned opening and closing apparatus, a part of the opening and closing lid may be held by being put between the key member and the elastic member by providing an elastic member on the front surface of the base table.
Additionally, there is provided according to another aspect of the present invention an opening and closing apparatus for opening and closing an opening and closing lid which closes an opening part of an accommodating box for accommodating an object to be processed and is locked by a locking mechanism,
characterized in that the opening and closing apparatus comprises:
a base table;
a key member mounted on the base table via a bearing mechanism in a state in which the key member is rotatable with respect to the base table;
a key member turning mechanism which turns the key member in either a normal or reverse direction;
an assist table positioned in front of the base table and urged by a spring member in a direction apart away from the base table;
horizontal moving means for moving the base table in a horizontal direction with respect to the accommodation box; and
vertical moving means for moving the base table in a vertical direction with respect to the accommodation box.
According to the above-mentioned invention, the locking mechanism can be unlocked by driving the vertical moving means and the horizontal moving means so as to insert the locking member into the key groove of the locking member of the opening and closing lid and turning the key member by the key member turning mechanism. When the key member is moved toward the opening and closing lid, the assist table provided on the front surface of the base table contacts the front surface of the opening and closing lid. At this time, the assist table presses the opening and closing lid by a spring force of the spring member. Accordingly, a part of the opening and closing lid is held by the spring force of the spring member by being put between the assist table and the key member. Then, in this state, the opening and closing lid is removed by moving the base table backward by driving the horizontal driving means. Since the opening and closing lid is sandwiched and held by the key member and the assist table, the opening and closing lid is prevented from being displaced with respect to the assist table, that is, the based table. Additionally, a part of the opening and closing lid may be held by being put between the key member and the elastic member by providing an elastic member on the front surface of the assist table. Further, it is preferable that the spring member be a coil spring provided between the base table and the assist table.
In the above-mentioned invention, it is preferable that at least two locking mechanisms be provided to the opening and closing lid, and a number of key members be equal to a number of the locking mechanisms.
Additionally, the key member turning mechanism may comprise an air cylinder generating a linear motion and a crank mechanism converting the linear motion into a rotating motion.
Alternatively, the key member turning mechanism may comprise: an air cylinder generating a linear motion; a belt driven by the air cylinder; and a pulley to which the key member is mounted, the pulley being rotationally driven by being engaged with the belt. According to this, the key member can be turned with a uniform torque, which prevents the key member from stopping in the middle of a turning operation.
Additionally, there is provided according another aspect of the present invention a processing system of an object to be processed which system has the opening and closing apparatus according to the above-mentioned present invention.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings